package client

import (
	"database/sql"
	"math"
	"os"
	"path/filepath"

	"forge.redroom.link/yves/meowlib"
	"github.com/google/uuid"
	_ "github.com/mattn/go-sqlite3"
	"google.golang.org/protobuf/proto"
)

func StoreMessage(peer *Peer, usermessage *meowlib.UserMessage, password string) error {
	var dbid string
	// If no db/no ID create DB + Tablz
	// TODO : if file size > X new db
	if len(peer.DbIds) == 0 {
		dbid = uuid.NewString()
		file, err := os.Create(filepath.Join(GetConfig().StoragePath, dbid+GetConfig().DbSuffix))
		if err != nil {
			return err
		}
		file.Close()
		peer.DbIds = append(peer.DbIds, dbid)
		sqliteDatabase, _ := sql.Open("sqlite3", filepath.Join(GetConfig().StoragePath, dbid+GetConfig().DbSuffix)) // Open the created SQLite File
		err = createTable(sqliteDatabase)
		if err != nil {
			return err
		}
		sqliteDatabase.Close()
		GetConfig().me.Save()
	} else {
		dbid = peer.DbIds[len(peer.DbIds)-1]
	}
	// Open Db
	db, _ := sql.Open("sqlite3", filepath.Join(GetConfig().StoragePath, dbid+GetConfig().DbSuffix)) // Open the created SQLite File
	defer db.Close()
	// Detach Files
	if len(usermessage.Files) > 0 {
		for _, f := range usermessage.Files {
			hiddenFilename := uuid.NewString()
			// Cypher file
			encData, err := meowlib.SymEncrypt(password, f.Data)
			if err != nil {
				return err
			}
			os.WriteFile(hiddenFilename, encData, 0600)
			// replace f.Data by uuid filename
			f.Data = []byte(hiddenFilename)
		}
	}
	// Encrypt message
	out, err := proto.Marshal(usermessage)
	if err != nil {
		return err
	}
	encData, err := meowlib.SymEncrypt(password, out)
	if err != nil {
		return err
	}
	// Insert message
	insertMessageSQL := `INSERT INTO message(m) VALUES (?) RETURNING ID`
	statement, err := db.Prepare(insertMessageSQL) // Prepare statement.
	if err != nil {
		return err
	}
	_, err = statement.Exec(encData)
	if err != nil {
		return err
	}
	return nil
}

// Get last messages from a peer
func GetLastMessages(peer *Peer, inAppMsgCount int, lastDbId int, wantMore int, password string) ([]InternalUserMessage, error) {
	var messages []InternalUserMessage
	fileidx := len(peer.DbIds) - 1
	// initialize count with last db message count
	countStack, err := getMessageCount(peer.DbIds[fileidx])
	if err != nil {
		return nil, err
	}
	// while the db message count < what we already have in app, step to next db file
	for inAppMsgCount > countStack {
		fileidx--
		if fileidx < 0 {
			return nil, nil
		}
		newCount, err := getMessageCount(peer.DbIds[fileidx])
		if err != nil {
			return nil, err
		}
		countStack += newCount
	}
	// There fileidx should provide the db that we need (unless wantMore overlaps the next DB)
	db, _ := sql.Open("sqlite3", filepath.Join(GetConfig().StoragePath, peer.DbIds[fileidx]+GetConfig().DbSuffix)) // Open the created SQLite File
	defer db.Close()
	//  if it's first app query, it won't hold a lastIndex, so let's start from end
	if lastDbId == 0 {
		lastDbId = math.MaxInt64
	}
	stm, err := db.Prepare("SELECT id, m FROM message WHERE id < ? ORDER BY id DESC LIMIT ?")
	if err != nil {
		return nil, err
	}
	defer stm.Close()
	rows, err := stm.Query(lastDbId, wantMore)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	for rows.Next() {
		var ium InternalUserMessage
		var um meowlib.UserMessage
		var id int64
		var m []byte
		err = rows.Scan(&id, &m)
		if err != nil {
			return nil, err
		}
		decdata, err := meowlib.SymDecrypt(password, m)
		if err != nil {
			return nil, err
		}
		err = proto.Unmarshal(decdata, &um)
		if err != nil {
			return nil, err
		}
		ium.dbid = id
		ium.message = &um
		messages = append(messages, ium)
	}
	// TODO DB overlap
	return messages, nil
}

func getMessageCount(dbid string) (int, error) {
	db, _ := sql.Open("sqlite3", filepath.Join(GetConfig().StoragePath, dbid+GetConfig().DbSuffix)) // Open the created SQLite File
	defer db.Close()
	var count int
	query := "SELECT COUNT(*) FROM message"
	err := db.QueryRow(query).Scan(&count)
	if err != nil {
		return 0, err
	}

	return count, nil
}

func createTable(db *sql.DB) error {
	createMessageTableSQL := `CREATE TABLE message (
		"id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,		
		"m" BLOB);` // SQL Statement for Create Table
	statement, err := db.Prepare(createMessageTableSQL) // Prepare SQL Statement
	if err != nil {
		return err
	}
	statement.Exec() // Execute SQL Statements
	return nil
}